tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License, or
5 * (at your option) any later version.
6 *
7 * This program is distributed in the hope that it will be useful,
8 * but WITHOUT ANY WARRANTY; without even the implied warranty of
9 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
10 * GNU General Public License for more details.
11 *
12 * You should have received a copy of the GNU General Public License
13 * along with this program; if not, write to the Free Software
14 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
15 *
16 * Copyright (C) IBM Corporation, 2011
17 *
18 * Authors: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
19 * Anton Blanchard <anton@au.ibm.com>
20 */
21#include <linux/uaccess.h>
22#include <linux/hardirq.h>
23
24int enter_vmx_copy(void)
25{
26 if (in_interrupt())
27 return 0;
28
29 /* This acts as preempt_disable() as well and will make
30 * enable_kernel_altivec(). We need to disable page faults
31 * as they can call schedule and thus make us lose the VMX
32 * context. So on page faults, we just fail which will cause
33 * a fallback to the normal non-vmx copy.
34 */
35 pagefault_disable();
36
37 enable_kernel_altivec();
38
39 return 1;
40}
41
42/*
43 * This function must return 0 because we tail call optimise when calling
44 * from __copy_tofrom_user_power7 which returns 0 on success.
45 */
46int exit_vmx_copy(void)
47{
48 pagefault_enable();
49 return 0;
50}